Help with program code re prime numbers
Please help! I'm trying to write a function that determines if a number is prime to use this function to determine and prints all prime numbers between 1 and 100. This is what I have so far:
#include <stdio.h>
int prime(int num)
{
int sw = 1;
int count:
}
for( count = num-1; count >=2; count--);
scanf("%d", &prime);
printf("%d\n", count, sw=1);
return 0;
}
Anna
I could help you with logic. May be u can implement it easily if you know some looping concept.
If you divide the number from 2 to (number-1), you should get some reminder then that number is prime.
FYI: 2 is the only even prime number.
Bye,
Juganoo
Thank you Juganoo for your help! I appreciate you!
Anna
The code of vVv is almost correct, but it also gives 1 as a prime number, which is incorrect. A number is prime if it has two divisors, 1 has only one divisor. So what you could do is count the number of divisors of a number, if it equals 2, then it is prime.
Code:int nr_of_divisors (int n) { int i, r = 0; for (i = 1; i <= n; i++) { if ((n % i) == 0) r++; } return r; }
